Centrifugal pump



Sept. 26, 1961 R. E. BAKER EFAL CENTRIFUGAL PUMP Filed March a, 1960 3 Sheets-Sheet 1 INVENTORS BY 4 1/55? Z 0 ATTORNEY Sept. 26, 1961 R. E. BAKER ETAL CENTRIFUGAL PUMP 3 Sheets-Sheet 2 Filed March 8, 1960 11v VENTORS' 42% 152 169 & Y @522 @r ATTORNEY P 1961 R. E. BAKER EE'AL 3,001,517

CENTRIFUGAL PUMP Filed March 8, 1960 3 Sheets-Sheet 3 INVENTORS ATTORNEY nite j States This invention relates to a pump, more particularly to a centrifugal pump for hydraulic fluid, and with regard to more specific aspects thereof to a coolant circulating pump for an internal combustion engine.

The invention contemplates a centrifugal pump having an improved inlet and outlet passage and pumping chamber configuration improving the overall efiiciency of the pump unit and having a housing construction defining such passage and chamber relationships, facilitating the mounting and removal of the pump unit for servicing and replacement on an internal combustion engine, and providing easy access for servicing of the pump shaft seal and inspection of the pump impeller. With regard to certain of its more specific aspects, the invention further contemplates a centrifugal pump particularly adapted for coolant circulating purposes in an internal combustion engine having a full-flow by-pass, radiator blocking type coolant system such as shown and described in greater detail in copending United States patent application Serial No. 1,488, filed January 11, 1960, in the names of Harold H. Albinson, George P. Hanley, Kenneth L. Hulsing, Harvey G. Humphries and John J. May, and entitled Two-Cycle Internal Combustion Engine.

The foregoing and other objects, advantages and features of the invention will be more apparent from the following description of a preferred illustrative embodiment, reference being made therein to the accompanying drawings in which:

FIGURE 1 is a front elevational view of an internal combustion engine having a water cooling system of the type indicated above and shows the operational environment of a centrifugal pump constructed in accordance with the invention;

FIGURE 2 is a fragmentry side elevational view of the pump mounting portion of the engine of FIGURE 1 with parts thereof broken away and in section to show certain details of the pump construction and its mounting and drive with respect to the engine substantially in the direction of the arrows and in the plane of the line indicated at 2-2 in FIGURE 1;

FIGURE 3 is a sectional view through the centrifugal pump and is taken substantially in the direction of the arrows and in the plane of the line indicated at 3-3 in FIGURE 2; and

FIGURE 4 is a fragmentary sectional view taken in the direction of the arrows and substantially in the plane of the line indicated at 44 in FIGURE 2.

Referring more particularly to the drawings, a twocycle internal combustion engine of V type is indicated generally by the reference numeral 10. This engine is preferably constructed as shown and described in the aforementioned application Serial No. 1,488 and has a liquid cooling system of a full-flow by-pass, radiator blocking type thus protecting the engine from excessive restriction of coolant flow during high load operation under cold weather conditions.

The engine includes a cylinder block 11 defining a lower crankcase portion 12 rotatably journalling the engine crankshaft 13 and an upper portion 14 defining Vd inline cylinder rows. Two cylinder heads 15 and 16 of the overhead valve and fuel injector type are secured to the inclined upper faces 17 and 18 of the cylinder block and close the upper ends of the several inline cylinders to define expansible combustion chambers with pistons tical thermostatic valves 31 therebetween.

Patented Sept. 26, 1961 ice reciprocably mounted therein. The combustion chamber defining portions of the cylinder block and heads are jacketed for coolant flow relative thereto. A positive displacement blower 19 is mounted on the cylinder block intermediate the cylinder heads 15 and 16 and is rotatively driven by the engine to supply scavenging air to a central air box extending longitudinally of the cylinder block. Two 'camshafts 20 and 21 are rotatively mounted and extend longitudinally through the cylinder block intermediate the cylinder rows just below the cylinder head and blower mounting decks of the block. These camshafts are rotatably driven in synchronous phased relation to the crankshaft 13 and are operable to sequentially actuate the several valves and fuel injectors associated with the adjacent cylinder heads to control the scavenging and charging of the engine cylinders.

Two thermostatic valve assemblies 25 and 26 are se cured to the front faces of the cylinder heads 15 and 16, respectively. The thermostatic valve assembly 25 comprises a lower inlet chamber defining housing member 27 and an upper outlet chamber defining housing member 28. The right thermostatic valve assembly 26 similarly includes a lower inlet chamber defining housing member 29 and an upper outlet chamber defining housing member 30. The lower housing members 27 and 29 have inlet ports mateable with outlet ports formed in the front jacket defining Walls of the cylinder heads 15 and 16, respectively. These mating ports are indicated at 23 and 24. The upper and lower housing members of the two valve assemblies are secured together and mount iden These thermostatic valves are preferably of the form described in greater detail with reference to FIGURE 19 of the aforementioned patent application Serial No. 1,488.

The thermostatic valves 31 each includea thermostatic pellet 32 operably connected to actuate a sleeve valve member 33 between a bypass full-opened position and a by-pass closed position. In their by-pass full-opened positions, the lower ends-0f the sleeve valve members 33 sealingly engage an annular valve seat member 34. In their by-pass closed positions, the upper ends of the valve members are sealingly engaged with respect to annular valve seats 35 and 36 defined by their associated upper housing members 28 and 30. The valve members 33 are slidably and sealingly mounted for reciprocation by openings 37 and 38 provided therefor in partition walls 39 and 4t dividing the upper housing members 28 and 29, respectively. The partition walls 30 and 40 divide the housing members 28 and 29 respectively into by-pass outlet chambers 41 and 42 and outlet chambers 43 and 44 which are connectable through flanged ports 45 and 46 to a common heat exchanger or radiator unit, not shown. Flanged ports 48 and 49 in the upper housing members 27 and 29 open on the by-pass outlet chambers 41 and 42 and are interconnected by a cross-over tube .47, the ends of which are secured thereto by flexible connections as shown. The right valve housing member 28 also defines an outlet T connection 48 merging the by-pass coolant flow from the chambers 41 and. 42.

The by-pass outlet48 is connected by a flexible tubing and clamp connection to an inlet port 51 defined by the housing 52 of a coolant circulating pump which is indicated generally by the reference numeral 50. The pump 50 is mounted on the front of the engine cylinder block by a gear housing and accessory support member 53. As described in greater detail below, the pump 50 is driven ofi the adjacent endof the left camshaft 28 through gears 54 and 55. The pump housing 52 defines a second inlet 56 which is of substantially equal capacity and. opposed to the by-pass inlet-51. The inlet 56 is connectable to the water outlet of the=engine radiator or heat exchanger.

3 The coolant is discharged from the pump 50 through a discharge scroll 57 through a pipe connection 58 to the coolant inlet, not shown, of an oil cooler unit 59. After passing through the cooler, the coolant is introduced through an elbow 60 into the cylinder block coolant passages and jacket compartments through the left side face of the block as indicated at 61 in FIGURE 1. From the cylinder block, the coolant passes into the cylinder head jackets and is discharged therefrom through the front outlet ports 23 and 24 and into the inlet chambers of the thermostatic valve assemblies 25 and 26. Depending upon the discharge water temperature, the thermostatic valve units 31 are independently operable to either proportion the fluid flow of its respective cylinder bank through both the by-pass and heat exchanger circuits within a limited temperature range or to direct the full coolant flow through either the. by-pass or the heat exchanger circuit.

Since each bank has its own thermostatic valve and housing tied into the common full-flow radiator and bypass circuits, the instant engine cooling system modulates the coolant temperatures into the cylinder block and provides substantial equalization of coolant flows and temperatures through the two cylinder banks. Complete closure of one thermostatic valve with the other open results in only a slight division of pump delivery between the two cylinder banks. Such a variation in fluid flow between the two banks tends to equalize the water outlet temperatures and thus the thermal response of the two thermostatic valves tends to equalize the distribution of coolant flow through the two banks.

Referring now in greater detail to the mounting, drive and structure of the pump 50, an end plate 62 is secured to and closes the upper front portion of the cylinder block. This end plate is perforated to embrace the ends of the camshaft 20 and 21 which project from the front end of the block. The gear 54 is drivingly secured to the front end of the left camshaft 20 and a pulley member 63 is drivingly secured on the right camshaft 21 and may be used to drive any suitable engine or vehicle accessory. The gear 54 is housed within a lubricant receiving drive compartment 64 defined between the front end plate 62 and the gear housing accessory mounting member 53. The member 53 includes a peripheral mounting flange 65 which is suitably secured to the front end plate and to the front of the engine block. A side wall 66 extends from the'mounting flange 65 to an end wall 67 which extends in spaced parallel relation to the end plate 62 and the mounting flange 65. The end wall 67 is provided with a circular opening 68 and has an annular face'69 adjacent thereto. The opening 68 is in spaced parallel relation to the common axis of the camshaft 2t) and the gear 54. The pump housing 52 is secured to the gear housing member 53 by three equiangularly spaced bolts 70 and closes the opening 68, having an annular face thereon at 7-1 which sealably engages the gear housing face 69.

The pump housing 52 defines an inlet chamber 72 intermediate and communicating with the opposed inlet passages 51 and 56 and a pumping chamber 74 embraced by the pressure outlet scroll 57 from which the coolant is discharged through the outlet opening or passage 57. The chambers 72 and 74 are partially separated by a partition web 73 having a central inlet opening 75 extending therethrough. An opening 77 is formed in the outer pumping chamber defining wall of the pump housing in axial alignment with the central inlet opening 75. The opening 77 is closed by a cover plate 76 which is secured to the housing member 52 by a plurality of bolts 76. The inlet chamber defining side of the pump housing is provided with three bosses 78, 78' and 78" extending radially of the mounting face 71 and provide holes for the pump mounting bolts 70. A Web 7 extends radially inwardly from the pump housing mounting face 71 to a cylindrical hub portion 86 coaxial with the openings 75 and 77. The hub portion 80 extends axially from the housing web 79 to provide a bearing supporting portion 81 projecting rearwardly into the drive compartment 64 and a forwardly extending seal mounting portion 82. The seal mounting portion 82 also defines a flow directing radius 83 adjacent the central inlet opening 75.

An impeller drive shaft 84 is journaled by bearings 85 and 86 longitudinally spaced and supported by the hub portion 81. The gear 55 is drivingly secured to the shaft 84 adjacent the end thereof projecting within the chamber 64. The opposite end of the impeller shaft projects into the pumping chamber 74 where a vaned impeller 87 is drivingly secured thereto by cooperating tapers indicated at 88 and by a clamping'nut 89. The bearings 85 and 36 are lubricated by oil spray centrifuged from gears 54 and 55 within the housing compartment 64; Properlubrication of the gear teeth may be effected either by gear tooth immersion or by a pressure jet discharging through an orifice communicating with one of the pressurized oil supply galleries of the engine. To insure proper lubrication of the bearing 86, the annular chamber 90 defined intermediate the bearings 85 and 86 is connected to the lubricant receiving drive chamber 64 by a pair of opposed ports '91 as well as through the bearing 85.

An oil seal 92 is interposed between the housing hub portion 82 and the impeller shaft 84 immediately forwardly of the bearing 86. This seal serves to seal the lubricant from the cooling water system of the pump. A water seal assembly 93 is interposed between the seal mounting hub portion 82, the shaft 84 and a seal ring 94 carried by the adjacent end of the impeller 87. An annular chamber 95 defined between the seals 92 and 93 is vented by a passage 96 which extends radially therefrom and terminates in an opening 96' outwardly of the mating faces of the pump housing and gearcover members. Any oil or water leakage from the opening 96" thus indicates a corresponding failure of either the oil or water seal.

it will be noted that the drive and mounting of the pump is'such that the pump may be replaced as a unit in service without disassembly of other engine components or accessories. The design of the pump also permits in place servicing of the seals $2 and 93 after removal of the pump cover plate 76 and the impeller 87.

As best seen in FIGURES 2 and 4, the impeller 87 comprises a central hub portion 97 and a radially extending peripheral flange portion 98 interconnected by an arcuate web 99. The flange portion 98 has radial running clearance 98' with the housing opening '77. For illustrative purposes this clearance is exaggerated in the several drawings, but in practice tends to seal the space between the back of the impeller and the cover plate 7 6 from the pressurized fluid in the outlet scroll. The impeller web 99 is perforated at 160, however, to equalize the pressures existing between the back of the impeller and the cover member with those at the compressor inlet. These vent openings may be threaded as shown to facilitate removal of the impeller from the shaft 84. Five vanes 101 extend longitudinally from the peripheral flange portion 98 and the adjacent outer portion of the web 99 and have running and sealing clearance 101' with a mating face 75 formed on the partition web 73 adjacent the opening 75. These vanes are curved to extend radially inwardly in the direction of impeller rotation and are of a configuration minimizing cavitation under and at the trailing edge of the several vanes thus improving overall pumping efficiency and increasing the effective capacity of the pumping unit.

The partition web 72 is reinforced by two webs 102 and 103. The web 162 extends between the partition web 73 and the mounting side of the pump housing member and radially bisects the fluid flow from the bypass inlet passage 51. The web 163 similarly bisects fluid flow from the radiator connected inlet passage 56 and extends between the partition web 73 and the hous:

ing boss defining the seal vent passage 96. The .partition web is further reinforced relative to the mounting side of the housing member by the bolt boss 78 and by a third web 104 Which extends radially therebetween on diametrically opposite sides of the inlet chamber in angularly spaced relation to the webs 162 and 103. This reinforcement of the web 73 maintains this relatively thin Wall partition against deflection by the discharge pressure to the outlet scroll 57. The outside wall of the pumping chamber and discharge scroll is reinforced against similar deflection by the boss defining the opening 77 and the plate secured thereto. The several webs 102, 103 and 104 terminate radially outwardly of the central inlet 75 and serve the further purpose of limiting the mass of Water into which swirl is induced adjacent the central inlet and hence the centrifugal forces acting on the water in the inlet chamber. This web construction thus coacts with the fixed configuration of the impeller vanes to provide maximum pumping displacement without cavitation through the normal impeller speed range and provides a rigid lightweight multi-inlet pump housing which is easily cored, cast and cleaned. The resultant pump and the drive and mounting therefor is also convenient and accessible for inspection, serving and unit replacement.

While the foregoing description has been limited to one illustrative embodiment of the invention, it will be appreciated that various changes and modifications might be made therein without departing from the spirit and scope of the invention, as defined in the following claims.

We claim:

1. A centrifugal coolant pump for an internal combustion engine having a full-flow by-pass engine cooling system, an engine driven means for driving various engine accessories, and a casing member housing said engine driven means and providing an accessory mounting location, said centrifugal coolant pump being mountable on the casing member in accessory drive location and comprising a housing member defining a pumping chamber at least partially embraced by a dischargescroll and an inlet chamber separated from said pumping chamher and discharge scroll by a partition web having a central pump inlet opening therethrough, the peripheral dimension of said inlet chamber being substantially greater than said inlet opening, said housing having inlet ports opening laterally into said inlet chamber on opposite sides thereof, one of said inlet ports being connectable to a thermostatic valve controlled by-pass and the other of said inlet ports being connectable to the outlet of a heat exchange unit, a flow dividing vane located inwardly of each of said inlet ports and extending longitudinally and radially between the partition web and the opposite inlet chamber Wall and terminating in spaced radial relation to said central inlet opening, the pump chamber defining wall of said housing member opposite said partition Web having an access opening therethrough in axial alignment with said centralinlet opening, a cover member secured to said housing member and closing said access opening to define one wall of said pumping chamber, the inlet chamberdefining Wall of said housing member opposite said partition web being adapted to be mounted on said drive casing in mating relation with said accessory drive location and having a cylindrical hub portion extending therefrom in axial alignment with said central inlet opening and pro jecting into said drive casing, an impeller shaft rotatably journaled within said hub and extending into said pumping chamber and drive casing, the drive casing end of said shaft being drivingly connectible to said engine driven means, and a vaned impeller drivingly secured to the opposite end of said impeller shaft within said pumpingchamber, said impeller being insertable through said access opening and having rotative pumping clearances with the partition web and the opposite pump chamber defining wall, said impeller having a plurality of vanes curved radially inwardly in the-directionof impellerrotation and terminating inwardly adjacent said inlet opening, said inlet chamber housing vanes limiting the swirl induced into the fluid coolant in the inlet chamber by the rotative suction effected by the impeller 'to the fluid adjacent said inlet opening and the curved configuration of said impeller vanes coacting with the limited vfluid swirl permitted by said housing vanes to means and providing an accessory mounting location, a

centrifugal coolant pump mounted on said casing member in said accessory drive location, said pump comprising a housing member defining a pumping chamber at least partially embraced by a discharge scroll and an inlet chamber separated from said pumping chamber and discharge scroll by a partition web having a central pump inlet opening therethrough, said inlet chamber having a peripheral dimension substantially greater than said inlet opening and a longitudinal dimension adjacent to said inlet opening which is substantially less than the diameter of said inlet opening, said housing having inlet ports opening laterally into said inlet chamber on opposite sides thereof, each of said inlet ports being of a size to supply full coolant flow therethrough, one of said inlet ports being connectable through a thermostatic valve controlled by-pass to the engine coolant outlet and the other of said inlet ports lbeing connectable through a thermostatic valve controlled heat exchange unit to the engine cooled outlet, the inlet chamber defining wall of said housing member opposite said partition web being adapted to be mounted on said drive casing in mating relation with said accessory drive location and having a cylindrical hub portion extending therefrom in axial alignment with said central inlet opening and projecting into said drive casing, an impeller shaft rotatably journaled within said hub and extending into said pumping chamber and drive casing, the drive casing end of said shaft being drivingly connected to said engine driven means, and a vaned impeller drivingly secured to the opposite end of said impeller shaft within said pumping chamber and having rotative pumping clearances with thepartition web and the opposite pump chamber defining wall.

3. In the combination set forth in claim 2, said pump housing having a flow dividing vane located inwardly of each of said inlet ports, said housing vanes extending longitudinally and radially between the partition web and the opposite inlet chamber wall and terminating in spaced radial relation outwardly of said central inlet opening thereby limiting the swirl induced into the fluid coolant within the inlet chamber by the rotative suction effected by the impeller to the fluid adjacent said inlet opening.

4. In the combination set forth in claim 3, said impeller having a plurality of vanes curved radially inwardly in the direction of impeller rotation and terminating inwardly adjacent said inlet opening, the curved configuration of said impeller vanes coacting with the limited fluid swirl permitted by said housing vanes to prevent cavitation under and at the trailing edge of the several impeller vanes.

5. In the combination set forth in claim 2, the pump chamber defining wall of said housing member opposite said partition web having an access opening therethrough in axial alignment with said central inlet opening, a cover member secured to said housing member to close said access opening and defining one wall of said pumping chamber, and said impeller being insertable through said access opening and having a plurality of vanes curved radially inwardly in the direction of impeller rotation and terminating inwardly at a radius substantially equal to that of said inlet opening.

6. In combination with an internal combustion engine 7 having a fluid cooling system, an engine driven means for driving various engine accessories, and a member providing an accessory mounting location relative to Said engine driven means, a centrifugal coolant pump mounted on'said member in said accessory, drive location, said pump comprising a housing member defining a pumping chamber at least partially embraced by a discharge scroll and an inlet chamber separated from said pumping chamber and discharge scroll by a partition web having a'central pump inlet opening therethrough, said inlet chamber having a peripheral dimension substantially greater than said inlet opening and a longitudinal dimension adjacent to said inlet opening which is substantially less than the diameter of said inlet opening, said housing having an inlet port disposed for lateral fluid flow into said inlet chamber, said housing member being adapted to be mounted on said mounting member in mating relation with said accessory drive location and having a cylindrical hub portion extending therefrom in axial alignment with said central inlet opening, an impeller shaft rotatably journaled within said hub and extending therethrough and into said pumping chamber, the drive adjacent end of said shaft being drivingly connected to said engine driven means, and a vaned impeller drivingly secured to the opposite end of said impeller shaft within said pumping chamber and having rotative pumping clearances with the partition web and the opposite pump chamber defining wall.

7. A centrifugal pump comprising a housing member defining a pumping chamber at least partially embraced by a discharge scroll and an inlet chamber separated from said pumping chamber and discharge scroll by a partition web having a central pump inlet opening there through, said housing having an inlet port disposed to introduce fluid flow substantially radially into said inlet chamber and said inlet chamber being of a peripheral dimension substantially greater than 'said inlet opening and having a relatively narrow longitudinal dimension adjacent to said inlet opening, and a driven vaned impeller rotatably journaled in said housing and having rotative pumping clearances with the partition web and the oppo site pump chamber defining wall. I

8. In a centrifugal pump as set forth in claim 7, said pump housing having vanes located on opposite sides of said inlet opening and disposed to divide the fluid inlet flow from said inlet port, said vanes extending longitudinally and radially between the partition web and the opposite inlet chamber wall and terminating in spaced radial relation to said central inlet opening whereby fluid swirl induced by the rotative suction effected by the impeller is limited in the inlet chamber to the fluid immediately adjacent said inlet opening.

9. In a centrifugal pump as set forth in claim 8, said impeller having a plurality of vanes curved radially inwardly in the direction of impeller rotation and terminating inwardly adjacent said inlet opening, the curved configuration of said impeller vanes coacting with the limited fluid swirl permitted by said housing vanes to prevent cavitation under and at the trailing edge of the several impeller vanes.

10. In a centrifugal pump as set forth in claim 7, said impeller having a plurality of vanes curved radially inwardly in the direction of impeller rotation and terminating inwardly adjacent said inlet opening, the curved configuration of said impeller vanes coacting with the swirl induced into the inlet chamber fluid as permitted by the narrow dimension of said inlet chamber to minimize cavitation under and at the trailing edge of the several impeller vanes.

11. A centrifugal pump comprising a housing member defining a pumping chamber at least partially embraced by a discharge scroll and a pump inlet chamber separated from said pumping chamber and discharge scroll by a partition web having a central pump inlet opening therethrough, said inlet chamber being of radial 8 dimension substantially greater than said inlet opening, said housing having an inlet port opening laterally into said inlet chamber on one side thereof and having a first vane located in said inlet chamber inwardly of and adjacent said inlet port and a second vane located on the side of said inlet chamber opposite said inlet port, said vanes extending longitudinally and radially between said partition web and the opposite inlet chamber defining housing wall and terminating'inwardly in radially spaced re lation to said central inlet opening to limit the swirl in duced by pump suction into the fluid in the inlet chamber to the fluid immediately adjacent the central inlet openings, and a vaned impeller .rotatably journaled by said housing within said pumping chamber, said impeller being in axial alignment with said inlet opening and having rotative sealing clearances with the pump chamber defining partition web and the opposite housing wall, said impeller having a plurality of vanes curved radially inwardly in the direction of impeller rotation and terminating inwardly adjacent said inlet opening, the curved configuration of said impeller vanes coacting with the limited fluid swirl permitted by said housing vanes to, prevent cavitation under and at the trailing edge of the several impeller vanes.

12. A centrifugal pump comprising a housing member defining a pumping chamber partially embraced by a dis charge scroll and a pump inlet chamber separated from said pumping chamber and discharge scroll by a partition web having a central pump inlet opening therein, said inlet chamber being of radial dimension substantially greater than said inlet opening and said housing having an inlet port opening laterally into said inlet chamber on one side thereof, said housing member having a cylindrical hub portion extending therefrom in axial alignment with said central inlet port opening, an impeller shaft spacedly embraced by and extending through said hub portion and into said pumping chamber, spaced bearing means rotatably supporting said impeller shaft with respect to said hub portion, a vaned impeller drivingly secured to said impeller shaft within said pumping chamber and having rotative sealing clearances with the pump chamber defining partition web and opposite pump chamber defining housing wall, a first seal means interposed between said sleeve portion and said shaft for sealing the lubricant supplied to said bearings from said pump housing chambers, a second seal means interposed between said sleeve portion and said shaft and impeller for sealing the pumped fluid from said first seal means and said bearing means, said first and second seal means defining a fluid receiving vent chamber therebetween, said housing defining a passage venting the chamber intermediate said seal means, said passage being defined by a boss extending radially from said vent chamber and bisecting the inlet flow from said inlet chamber port, said housing having a flow dividing vane located radially inwardly of said inlet port, said flow dividing vane extending between said partition web and the inlet chamber defining housing wall and terminating radially outwardly of said central inlet opening.

13. A centrifugal pump comprising a housing member defining a pumping chamber at least partially embraced by a discharge scroll and a pump inlet chamber separated from said pumping chamber and discharge scroll by a partition web having a central pump inlet opening therethrough, said inlet chamber being of radial dimension substantially greater than said inlet opening, said housing having an inlet port opening laterally into said inlet chamber on one side thereof, a vaned impeller'rotatably journaled by said housing within said pumping chamber in axial alignment with said inlet opening and having rotative sealing clearances with the pump chamber defining partition web and the opposite housing wall, and said housing having a first flow dividing vane located in said inlet chamber inwardly of and adjacent said inlet port and a second flow dividing vane located on the opposite 9 side of said inlet chamber, said flow dividing vanes extending longitudinally between said partition web and the inlet chamber defining housing wall and terminating inwardly in radially spaced relation to said central inlet opening.

14. A centrifugal pump mountable in a suitable accessory drive location on an internal combustion engine and adapted to provide engine coolant circulation, said pump comprising a housing member defining a pumping chamber at least partially embraced by a discharge scroll and a pump inlet chamber separated from said pumping chamber and discharge scroll by a partition web having a central pump inlet opening therethrough, the peripheral dimension of said inlet chamber being substantially greater than said inlet opening, said housing having an inlet port opening laterally into said inlet chamber on one side thereof, the pump chamber defining wall of said housing member opposite said partition web having an access opening therethrough in axial alignment with said central inlet opening, a cover member secured to said housing member and closing said access opening to define one wall of said pumping chamber, the inlet chamber defining Wall of said housing member opposite said partition web being adapted to be mounted on said engine in mating relation with said accessory drive location and having a cylindrical hub portion extending therefrom in axial alignment with said central inlet opening, an impeller shaft rotatably journaled within said hub and extending into said pumping chamber, a vaned impeller drivingly secured to said impeller shaft within said pumping chamber and having rotative pumping clearances with the partition Web and the opposite pump chamber defining wall, and said housing having a first flow dividing web located inwardly of said inlet port and a second flow dividing web located on the side of said inlet chamber opposite said inlet port, said flow dividing webs extending between the partition web and the inlet chamber defining, pump mounting wall of said housing and terminating in spaced radial relation outwardly of said central inlet opening.

15. A centrifugal pump mountable in a suitable accessory drive location on an internal combustion engine and adapted to provide coolant circulation in a full-flow bypass engine cooling system, said pump comprising a housing member defining a pumping chamber at least partially embraced by a discharge scroll and a pump inlet chamber separated from said pumping chamber and discharge scroll by a partition web having a central pump inlet opening therethrough, said inlet chamber being of radial dimension substantially equal to said pumping chamber and scroll, said housing having inlet ports opening laterally into said inlet chamber on substantially opposite sides thereof, the pump chamber defining wall of said housing member opposite said partition web having an access opening therethrough in axial alignment with said central inlet port opening, a cover member secured to said housing member and closing said access opening to define one wall of said pumping chamber, the inlet chamber defining wall of said housing member opposite said partition web having a cylindrical hub portion extending therefrom in axial alignment With said central inlet port opening, an impeller shaft spacedly embraced by and extending through said sleeve portion and into said pumping chamber, spaced bearing means rotatably supporting said impeller shaft with respect to said housing hub portion, a vaned impeller drivingly secured to said impeller shaft within said pumping chamber and having rotative sealing clearance With said partition web and pump chamber defining wall adjacent the central inlet and access openings, a first seal means interposed between said sleeve portion and said shaft for sealing the lubricant supplied to said bearings from said pump housing chambers, a second seal means interposed between said sleeve portion and said shaft and impeller for sealing the pumped fluid from said first seal means and said bearing means, said first and second seal means defining a fluid receiving vent chamber therebetween, said housing defining a passage venting the chamber intermediate said seal means, said passage being defined by a boss extending radially from said vent chamber and bisecting the inlet fiow from one of said inlet chamber ports, and said housing having a flow dividing web or vane located radially inwardly of each of said inlet ports, said flow dividing vanes extending radially and longitudinally between said partition web and said inlet chamber defining housing wall and terminating radially outwardly of said central inlet opening.

References Cited in the file of this patent UNITED STATES PATENTS 1,366,149 Applin Jan. 18, 1921 1,461,711 Bull July 10, 1923 2,069,640 Beardsley Feb. 2, 1937 2,852,009 Turlay Sept. 16, 1958 2,922,374 Perish Jan. 26, 1960 

